Why wouldn't he be serious? As more and more people spew forth garbage onto the Internet, we just end up wasting more and more of each others' time. For god sakes, look at Twitter! Maybe there's some useful information in there sometimes, but for the most part it is pure noise -- and look how it's taking off! It's as if people would rather waste time both creating and consuming fluff than to spend the time to create and consume content that is actually worth something.

My sense is that he's completely sincere about the whole thing.

He amplified the opinions expressed here in this talk with John Gruber: http://www.43folders.com/2009/03/25/blogs-turbocharged